How do you tell if an elephant is having a good day? Or spy on the nocturnal squid-catching skills of the albatross?

The BBC reports that last week at the British Science Festival‌, Prof Rory Wilson of Swansea University divulged the secrets of the animal kingdom, including penguin diving habits, albatross hunting methods and the emotional states of elephants.

"The problem with animals is we often want to know things about them that they don't want to tell us or that aren't easy to find out. The only way to do it is to put something on [the animal] that will accompany it," Prof Wilson said.

His work was all made possible by a small electronic chip his team developed specifically to stalk animals in their private hours.

This chip contains accelerometers, magnetometers, pressure, temperature and light sensors - offering an unprecedented view of an animal's life.

The tag, Prof Wilson explained, essentially does exactly what our smartphones or fitness monitors do, continually tracking and recording the wearer's position and movements.

"This is a novel written by an animal. It's very exciting to be the first person to open that novel."

So far the group at Swansea has chronicled the lives of more than 1000 animals and 100 different species including penguins, cheetahs, sloths, albatrosses, elephants, cormorants and leopards.

"Our current understanding of animal behaviour is biased by what we perceive animals to be capable of, and what we see them doing," said Prof Wilson, alluding to a world of hidden behaviour.

"Elephant seals are big fat lumps of jelly on the beach, but become beautiful ballerinas in the sea."